After a well is drilled and a target reservoir has been encountered, a completion and production operation are performed, which may include sand control processes to prevent formation sand, fines, and other particulates from entering production tubing along with a formation fluid. Typically, one or more sand screens may be installed along the formation fluid flow path between production tubing and the surrounding reservoir. Additionally, the annulus formed between the production tubing and the casing (if a cased hole) or the formation (if an open hole) may be packed with a relatively coarse sand or gravel during gravel packing operations to filter the sand from the formation fluid. This coarse sand or gravel also supports the borehole in uncased holes and prevents the formation from collapsing into the annulus.
Generally, gravel packing operations include placing a lower completion assembly downhole within the target reservoir. The lower completion assembly may include one or more screens along the production tubing that is disposed between packer assemblies. A packer assembly may be located on the “uphole” or “heel side” (the side of the screen closest to the heel of the well or the uphole end of the completion assembly), on the “downhole” or “toe side” (the side of the screen closest to the end or the toe of the well), or both. After the lower completion assembly is placed in the desired location downhole, the packer assemblies are set (e.g., expanding or swelling the packer) to define zones within the annulus. Each zone is then gravel packed separately and independently, typically using a service tool that is run downhole. The service tool opens a valve mechanism associated with a first zone to allow access from the tubing into the annulus associated with the first zone. A fluid slurry containing gravel is pumped through the valve mechanism to fill the annulus associated with the first zone while the fluid within the slurry returns through the screens. After the first zone is packed, the service tool is moved up to close the valve mechanism in the first zone and to open the valve mechanism in a second zone. Thus, each are placed in a pumping position.
In “fishhook” wells, which have uphill wellbore geometries, or wellbore geometries within the 120 to 130 degree deviation range, gravel packing operations that fill the annulus in the “toe to heel” direction or opposite direction from the normal operations. Reverse positioning associated with fishhook wells creates high friction forces and is problematic to establish the needed pumping positions.
The present disclosure is directed to a post gravel pack sealing assembly and methods that overcome one or more of the shortcomings in the prior art.